Retailers and natural history experts called on to provide information on exotic foods such as crickets and worm crisps

Britons used to sing a nursery rhyme about swallowing a fly, bushtucker trials have become an excruciating staple of TV's "I'm a celebrity, get me out of here" and stores and online suppliers are selling exotic snacks such as crickets and worm crisps.

Now food standards watchdogs across the European Union are preparing to give them safety tests. Though such dishes are being increasingly seen as the food of the future for affluent as well as poorer societies, the European commission in Brussels and agencies in members states haven't a clue about how many citizens are now eating the foods.

They are asking suppliers, retailers and natural history experts to help them establish just how far down the road Europeans are in following other nation's dietary habits, such as cockroaches (China), witchetty grubs (Australia), locusts (many places in Africa) and agave worms (Mexico, where they accompany tortilla as well as tequila).

Enthusiasts say the foods, cooked, are a dependable source of protein and don't take up the farmland feeding livestock – or the greenhouse gases affecting climate change.

But the bad news for importers is that if their foods have not been consumed "to a significant degree" in Europe before May 1997, they will have to undergo tests. The wording of so-called novel foods legislation has meant that such foods have so far been overlooked but that exemption about to change, as a letter from the UK's Food Standards Agency makes clear.

It invites companies and other interested parties, including the Natural History Museum to "submit any relevant information on consumption of whole insects and other animals, such as worms, within the UK, including information relating to the species that are currently sold in the UK and the duration and extent of sales."